Optimization of a headspace solid-phase microextraction and gas chromatography/mass spectrometry procedure for the determination of aromatic amines in water and in polyamide spoons

摘要

In this work, a headspace solid-phase microextraction and gas chromatography coupledwith mass spectrometryud(HS-SPME-GC/MS) method for trace determination of primary aromatic amines was developed. The followingudanalytes were investigated: aniline (A), 4,4′-diaminodiphenylmethane (4,4′-MDA) and 2,4-diaminotolueneud(2,4-TDA) using 3-chloro-4-fluoroaniline (3C4FA) and 2-aminobiphenyl (2ABP) as internal standards. Prior toudextraction the analytes were derivatized in the aqueous solution by diazotation and subsequent iodination.udThe derivativeswere extracted byHS-SPME using a PDMS/DVB fiber and analyzed by GC/MS. A D-optimal designudwas used to study the parameters affecting the HS-SPME procedure and the derivatization step. Two experimentaludfactors at two levels and one factor at three levels were considered: (i) reaction time, (ii) extraction temperature,udand (iii) extraction time in the headspace. The interaction between the extraction temperature andudextraction time was considered in the proposed model. The loadings in the sample mode estimated by audPARAFAC (parallel factor analysis) decomposition for each analyte were the response used in the design becauseudthey are proportional to the amount of analyte extracted. The optimum conditions for the best extraction of theudanalytes were achieved when the reaction time was 20 min, the extraction temperature was 50 °C and theudextraction time was 25 min. The interaction was significant.udA calibration based on a PARAFAC decomposition provided the following values of decision limit (CCα): 1.07 μgL−1udfor A, 1.23 μg L−1 for 2,4-TDA and 0.83 μg L−1 for 4,4′-MDA for a probability of false positive fixed at 5%. Also, theudaccuracy (trueness and precision) of the procedurewas assessed. Furthermore, all the analyteswere unequivocallyudidentified.udFinally, the method was applied to spiked water samples and polyamide cooking utensils (spoons). 3% (w/v)udacetic acid in aqueous solution was used as food simulant for testing migration from polyamide kitchenware.udDetectable levels of 4,4′-diaminodiphenylmethane and aniline were found in food simulant from some of theudinvestigated cooking utensils.